Toggle hopper door operating mechanisms

ABSTRACT

A hopper structure includes a bottom discharge arrangement having hinged doors which are movable to open and closed positions and which include an operating mechanism providing for an initial limited horizontal movement of said doors to disengage them from a locked and supported engagement with the hopper structure and whereupon doors are opened by gravity. The operating mechanism includes a manually actuated operating head which can be indexed to certain positions and with a suitable tool the operator can in one position close said door and in the other position open the same.

United States Patent [72] Inventor Ernest J. Nagy Munster, Ind. [21] Appl. No. 835,609 {22] Filed June 23,1969 [45] Patented Oct. 12, 1971 [73] Assignee Pullman Incorporated Chicago, Ill.

[54] TOGGLE HOPPER DOOR OPERATING MECHANISMS 14 Claims, 11 Drawing Figs.

[52] US. Cl 105/253, 105/282 R, 105/290, 105/304, 105/311 R [51] Int. Cl 861d 7/18, B61d 7/20, 861d 7/26 [50] Field of Search 105/247, 248, 249, 250, 251, 252, 253, 280, 281, 283, 296, 299, 304, 308, 308 C, 308 E, 308 P, 309, 311, 311 C, 282 R, 290,311 R [56] References Cited UNITED STATES PATENTS 1,949,555 3/1934 Woehle 105/309 X 2,042,528 6/1936 Hosceit 105/283 X 2,720,173 10/1955 Dorey 105/280 3,137,247 6/1964 Hamilton et a1. 105/251 3,291,071 12/1966 Dorey 105/253 3,315,859 4/1967 Owen, Jr. etal. 226/21 3,316,859 5/1967 Floehr 105/253 3,339,500 9/1967 Dorey 105/253 Primary ExaininerArthur L. La Point Assistant Examiner-Howard Beltran Attorneys-Hilmond O. Vogel and Wayne Morris Russell PATENIEIluIzIIzIan. 3,611.94?

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TOGGLE HOPPER DOOR OPERATING MECHANISMS SUMMARY The prime objective of the invention is to provide an improved operating mechanism for the discharge gate of a hopper wherein the gate moves hingedly to open and closed positions and during opening is moved to said position by gravity. The operating mechanism includes an overcenter linkage arrangement which is actuated by a rotatable shaft and is connected to the gate which includes a downwardly swinging doors. A hinge construction connecting the doors to a frame structure of the hopper permits the door to initially be moved horizontally to a position wherein end portions of the doors are disengaged from a locked or supporting relation with respect to the frame and the doors are swung open by gravity. Upon closing of the doors they are first pivoted by the mechanism to a closed position and continued actuation provides for horizontal movement of said doors to their engaged or locking position relative to the supporting structure of the hopper.

Another feature of the invention is an improved operating head for rotating the door opening mechanism upon which the insertion of a rod, in one position of the head, opens the doors and in another position of the head closes said doors. The head includes camming means which disengages the rod from connection therewith to protect the operator during gravity opening of said doors.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a plan view of a hopper discharge engagement, partially in section, disclosing a pair of laterally spaced discharge openings and gates therefor;

FIG. 2 is a cross-sectional view taken substantially along the line 2-2 of FIG. 1;

FIG. 3 is a crosssectional view taken substantially along the line 3-3 of FIG. 1;

FIG. 4 is a detail view taken substantially along the line 4-4 of FIG. 1;

FIG. 5 is a cross-sectional view taken substantially along the line 5--5 of FIG. 1;

FIG. 6 is a view similar to FIG. 5 showing an operating position of a closure member;

FIG. 7 is a view taken substantially along the line 7-7 of FIG. 5;

FIG. 8 is a sectional vie taken along the line 8-8 of FIG. 1;

FIG. 9 is a plan view of the operating head mechanism shown in FIG. 8;

FIG. 10 is a plan view showing an actuating rod in engagement with an operating head to provide for rotation therefor; and

FIG. 11 is another position of said operating head showing the disengagement of a rod utilized for actuating the said head.

DETAILED DESCRIPTION Referring now particularly to FIG. I a hopper discharge arrangement is designated by the reference character 10. The discharge arrangement 10 comprises a pair of hoppers 11 positioned in side-by-side relation each including sloping walls 12 connected to provide a rectangular configuration. A pair of vertically extending and longitudinally disposed sidewalls 13 are disposed beneath each of the hoppers 11 and are suitably connected to the walls 13 to provide a discharge opening 15 as best indicated in FIG. 2. Walls 14 depend downwardly from angle-shaped frame members 16 and 17 as best shown in FIG. 3. The frame members 16 and 17 are connected to longitudinally angle-shaped frame members 18 each of which is disposed at opposite ends of the frame members 16 and 17.

As best shown in FIGS. 1 and 2 a pair of longitudinally extending and transversely spaced cross members 19 and 20 are suitably supported on the upper flanges of the frame members 16 and 17. Gussets 21 are connected to the cross members 19 and 20 and project downwardly with respect thereto. As best shown in FIGS. 1, 2 and 4 a longitudinally inverted V-shaped angle member 22 is connected to the walls 13 and includes flange portions23. A plurality vertical brackets 24 are suitable connected to the underneath sides of the flanges 23 and are spaced longitudinally along said bracket member 22. The brackets 24 have rigidly connected thereto and support a longitudinally extending tube 25 forming a bearing means for a shaft 26 which is rotatable therein. FIGS. I and 2 show only an approximate three-quarter portion of the arrangement 10 but both sides are symmetrical and a supporting bearing 27 (FIG. 8) projects downwardly from the frame members 18 to support the ends of the shaft 26. An operating head generally indicated at 28 is connected to each end of the shaft 26 to provide for rotation thereof.

As best shown in FIG. 3 two doors 29 are provided to regulate each discharge opening 15. Each door 19 comprises a sidewall 31 longitudinally spaced end walls 23 and open end portions 33 as indicated in FIG. 4. Each end portion 33 may in the closed portion of the doors be suitably supported on a ledge 34 provided by indentations formed in each of the vertical brackets 24. Each if the doors 29 also is provided with a longitudinally extending U-shaped bracket 35 having hinge pins 36 projecting outwardly from the ends thereof. Opposite ends of the U-shaped brackets 35, as best shown in FIG. I are interconnected by means of pins 37 as best shown in FIG. 1.

The shaft 26, as best shown in FIG, 3, is provided at its intermediate and opposite ends with throw arms 38. An upper link 39 is connected to one of the throw arms 38 and extends above the shaft 26 and is suitable connected to one of the throw arms 38 by means of a pivot connection 41. A lower link 40 extends underneath the shaft 26 and is connected by means of a pivotal connection 42 to the other of the throw arms 38. Links 39 and 40 are suitably connected to the pivotal connections or hinge pins 36 and 37 as best shown in FIGS. 1 and 3, so that upon actuation of the shaft 26 the links 39 and 40 move the doors to open and closed positions as will be described below.

Referring now particularly to FIGS. 3, 5, 6 and 7, hinge mechanisms are generally referred to, by the reference character 43. Each hinge mechanism 43 comprises a plate 44 rigidly supported on the angle-shaped frame members 16 and 17 and each has connected thereto a cylindrical hinge member 45. Each hinge member 45 is provides with an inwardly facing slots 46. A cylindrical member 47 is suitably retained within each hinge member 45 and is rotatable therein. Each cylindrical member 47 includes an elongated recess 48 which, as shown in FIG. 5, in one position is in registry of alignment with each slot 46. Each door 29 is provided at comers thereof adjacent the sidewalls 31 with a pair of slide members or lugs 49, as best shown in FIGS, 5 and 6. Each lug 49 is provided with opposed arcuate ends 50 as best shown in FIG. 6. The arcuate ends 50 complement the shape of one end of the recess 48, and as best shown in FIG, 6 also complement the inner peripheral surface of the cylindrical hinge member 45.

As best shown in FIGS. 8 through 11, the operating head 28 includes a U-shaped yoke member 51 having a base 52 suitably welded to the shaft 26, said yoke 51 including arms 53 between which an actuating element 54 is positioned in relative rotatable relation by means of a pivot pin 55. One end of the actuating element 54 is provided with an upper jaw 56 and a lower jaw 57. The other end of the element 54 is provided with an upper jaw 58 and a lower jaw 59. The upper jaw 56 is provided with an inclined cam surface 61 sloping toward the pivot pin 55 in the position of the actuating element 54 as shown in FIG. 9. The lower jaw 57 is provided with a camming surface 62 which is disposed in cruciform relation relative to the surface 61 and slopes in an opposite direction toward the pivot pin 55. Thus the camming surface 61 is disposed in the position of FIG. 9 above the camming surface 62. The upper jaw 58 is provided with a camming surface 63 which slopes in the same direction and toward the camming surface 61. The lower jaw 59 is provided with a camming surface 64 which slopes in a direction toward the pin 55. The camming surfaces 63 and 64 therefore are also disposed in relative cruciform relation. The operation of the camming surfaces will be described hereinafter.

A sleeve 65 is slidable in the yoke 51 from the dotted line position shown in FIG. 8 to the full-line position. The sleeve 65 is provided with a stop finger 66 and includes an opening 67 as best shown in FIG. 11. The opening 67 in the full-time position shown in FIG. 8 is adapted to register with an opening 68 provided in a vertical bracket 69 rigidly secured to the frame 17. In the position shown, a car seal 70 is inserted through the openings 67 and 68 and the operating head 28 and shaft 36 are secured and locked against rotation As best shown in FIG. I] an operating rod 71 is disposed between the jaws 56 and 57 to effectuate rotation of the shaft 26.

THE OPERATION FIGS. 1 and 2 disclose a pair of laterally disposed gate arrangements for a side-by-side hopper arrangement. The arrangement if the elements is Such that upon actuation of one set of doors the others are also simultaneously operated. The operating head arrangement and gate elements are symmetrical on opposite sides of the centerline of a hopper or hopper car arrangement. In FIGS. 1 and 2 the doors are shown in a closed position. The operating head 28 in FIGS. 1 and 2 is in a locked position since the finger 66 is in engagement with bracket 69 thus preventing rotation of the shaft 26 tending to move the links 39 and 40 to their open position. Upon removal of the car seal 70, the sleeve 65 is moved outwardly from the frame member 18 so that finger 66 can now clear the bracket 69 and thus the actuating element 54 and the shaft 26 can be rotated. The operator inserts the operating bar 71 into the opening 60 between the jaws 56 and 57. The bar 71 by virtue of the disposition of the jaws 56 and 57 operates to exert a downward force on the jaw 57 and an upward force on the jaw 56 thereupon rotating the actuating element 54 in turning rotating the shaft 26 which in the position of FIG. 3 is in a counterclockwise direction thereby forcing the arms 39 and 40 to exen an outward horizontal force. The horizontal forces thus exerted move the lugs 50 from the position shown in FIG. 5 completely into the elongated recess 48 in each end of each door so that the lugs now are free to rotate with the cylindrical member 47 in the cylindrical hinge member 45. In the closed position, as shown in FIG. 4, the leading edges or edge portions 33 of each of the doors 29 is supported on the spaced vertical brackets 24 of the horizontal bracket 22 which forms a support for the shaft 26, By virtue of the horizontal forces exerted by the links 39 and 40 the leading edges 33 are moved free of the ledges 34 and the doors 29 are now free to drop to the dotted line position of FIG. 3. The doors 29 drop by gravity and of course in event of a load within the hoppers 11 the weight of the material causes the doors 19 to move rapidly to their open position without any possibility of malfunction, hang-up, etc.

During the insertion of the rod 71 between the jaws 56 and 57 the operation is protected against injury which might be occasioned by the fast operating of the doors 29 during their movement to the open position. The camming surfaces 61 and 62 are so disposed as to cause an outward movement against the bar 71 which dislodges the bar 71 from the recess 60 as the operating head 28 is being rotated in response to the opening action of the doors 29.

In order to close the doors 29 the actuating element 54 is rotated so that the jaws 58 and 59 are now in the outwardly facing position for insertion of the rod 71 into the opening 60. The operator exerts a pressure on the rod 71 whereupon a downward force is exerted in the jaw 59 and upward force is exerted on the jaw 58 providing for rotation of the shaft 26, in the view shown in FIG. 3, in a clockwise direction. As the shaft 26 moves in this clockwise direction a force is created on the links 39 and 40 which moves the doors 29 toward the closed position with rotation of the cylindrical members 47 within the hinge members 45. When the doors are disposed substantially in a horizontal position, continued movement of the links to the overcenter position shown in FIG. 3 provides a thrust inwardly directed thrust on the hinge pins 36 and 37 in turn causing movement of the leading edges 33 of the doors 29 into supported relation with the ledges 34 of the vertical brackets 24. During this movement of the lugs 49, as shown in FIG. 5, move outwardly of the recesses 48 and through the slots 49 of the cylindrical hinge members 45. In this position shown in FIG. 5, it is apparent that the lugs 49 are disposed across the slot 46 and leading edge or ends 33 are firmly supported on the horizontal bracket and are effectively supported against opening movement. The links 39 and 40 are disposed in overcenter relation with respect to the shaft 26 as indicated in FIG. 3. Both ends of the doors 29 therefore are firmly supported against opening movement. Thus it is apparent that a unique quickoperating hopper discharge and gate arrangement has been disclosed which provides for positive opening and closing actions, and in the closed position, is effectively secured and locked. Further, a novel operating head for actuating the door operating mechanism is disclosed which provides for maximum safety during the operation.

What is claimed is:

1. In a hopper having a discharge opening for discharging material therefrom, a frame supported by said hopper, the improvement comprising:

a door having a first hinged end and a second free end in opposition thereto, hinged connected means hingedly connecting said first end of said door to said frame for movement between open and closed positions relative to said discharge opening,

other means on said frame supporting the second free end of said door in the closed position,

means on said hinged connecting means providing generally limited horizontal movement of said door, and

further means on the frame adjacent the second end of the door and pivotally connecting with the door intermediate it said ends for movingly carrying said door generally horizontally in a direction whereby said second end of said door is moved generally horizontally out of supported engagement with said other means supporting on said frame, whereby said door is pivoted at its first end by gravity to said open position.

2. The invention in accordance with claim I,

said further means for moving said door including a rotatable member in said frame,

an arm connected to said member for movement therewith,

a link having one end pivotally connected to said door hinged end and another end pivotally connected to said arm, and

said rotatable member during rotation moving said door to a closed position whereby said pivotal connection of said arm and link are moved to an overcenter position relative to the axis of said rotatable manner. 3. The invention in accordance with claim I, other said means supporting said second end of said door including a horizontally extending member on said frame including generally horizontal edge portions receiving the second end of said door in supporting engagement, and

said second end being slidably out of said supporting during horizontal movement of said door.

4. The invention in accordance with claim 1,

said means on said hinged connecting means including a slot extending horizontally in the closed position of said door, and

a slidable element on said first end of said door slidable disposed in said slot.

5. In a hopper having a discharge opening for discharging material therefrom, a frame supported by said hopper, the improvement comprising:

a door including means hingedly connecting one end of said door to said frame for movement between open and closed positions relative to said discharge opening,

means on said frame supporting a second end of said door in the closed position,

means on said hinged connecting means providing limited horizontal movement of said door,

means for moving said door horizontally in a direction whereby said second end of said door is moved horizontally out of supported engagement with said supporting means on said frame, whereby said door is pivoted by gravity to said open position,

said means supporting said second end of said door including a horizontally extending member on said frame including horizontal ledge portions receiving the second end of said door in supporting engagement,

said second end being slidably out of said supporting engagement during horizontal movement of said door,

said means on said hinged connecting means including a slot extending horizontally in the closed portion of said door,

a slidable element of said one end of said door slidably disposed in said slot,

said means on said hinged connecting means including a cylindrical hinge member supported on said frame,

said hinge member having an opening,

a second cylindrical hinge member rotatably positioned with said first hinge member containing said slot,

said slot and said opening being in horizontal registry during the closed position of said door, and

said slidable element being partially disposed in said slot and having said opening preventing rotation of said second cylindrical member.

6. The invention in accordance with claim 5,

said slidable element being movable horizontally with said door into said slot to one side of said opening whereby said means for moving includes a rotatable member which upon disengagement of said second end hingedly rotates with said door to said open position.

7. In a hopper having a discharge opening for discharging material therefrom, a frame including horizontally spaced frame members disposed on sides of said opening, the improvement comprising:

a horizontal support on said frame extending adjacent said opening between said frame members;

a pair of doors, I

a hinge mechanism for connecting each of the first ends of each of said doors to each of said frame members for hinging movement between open and closed positions relative to said discharge opening,

each said hinge mechanism including a hinge bracket connected to said respective frame member,

a rotatable member rotatably supported on said hinge bracket,

said rotatable member including a slot,

a slidable element connected to said first end of each door engaging said slot in relative sliding relation, each said door including a second end supported on said horizontal support in the closed position of said doors, and

means on said frame pivotally interconnecting with each of the doors intermediate their said ends for moving said doors horizontally whereby said second ends of said doors are disengaged from supported relation relative to said horizontal support and said doors are moved by gravity to an open position.

8. The invention in accordance with claim 7,

said means on said frame for moving said doors horizontally including a shaft rotatably supported on said horizontal a pair arms projecting in opposite direction from said shaft and rotatable therewith, first and second links respectively connected to said doors, one link, in a closed position of said door, extending over said shaft and pivotally connected to one of said arms, said other link extending beneath said shaft and being pivotally connected to said other arm, and

said pivotal connection of said links to said arms being disposed overcenter relative to the axis of said shaft.

9. In a hopper having a discharge opening for discharging materials therefrom, a frame including horizontally spaced frame members disposed on sides of said opening, the improvement comprising:

a horizontal support on said frame extending adjacent said opening said frame members,

a pair of doors,

a hinge mechanism connecting first ends of said doors to said frame members for hinging movement between open and closed positions relative to said discharge opening,

each said hinge mechanism including a hinge bracket connected to said frame member,

a rotatable member rotatably supported on said hinge bracket,

said rotatable member including a slot,

a slidable element connected to said first end of each door engaging said slot in relative sliding relation,

each said door including a second end supported on said horizontal support in the closed position of said doors,

means on said frame for moving said doors horizontally whereby said second ends of said doors are disengaged from supported relation relative to said horizontal sup port and said doors are moved by gravity to an open position,

each said hinge bracket including a cylindrical member,

said rotatable member including a second cylindrical member rotatably supported within said first cylindrical member,

said slot being disposed in said second cylindrical member,

said first cylindrical member having an opening in the closed position of said doors being in registry with said slot,

said slidable element being disposed in said opening and slot in the closed position of said door whereby said second cylindrical member is fixed against rotation, and

said slidable element being movable to one side of said opening into said slot during disengagement of said second end of each said door during movement to its open position.

10. The invention in accordance with claim 9,

said horizontal support including a plurality of horizontal ledges supporting the ends of said doors.

11. The invention in accordance with claim 10,

said supporting means having a rotating shaft supported thereon and means for moving said doors including linkages pivotally connected to said doors and said shaft.

12. In a hopper discharge structure including a frame, a door hingedly connected to said frame for movement to open and closed positions, mechanism for actuating said door whereby it moves by gravity to an open position including a shaft rotatably mounted on said frame, the improvement comprising:

an operating hear for rotating said shaft including arm means having an element carried thereby, said element having a pair of laterally spaced jaws defining therebetween an open end tool-receiving recess,

each jaw having a camming surface, said jaws being disposed to rotate said shaft in one direction during the normal insertion of a tool withing said recess, and

said camming surfaces being operative to disengage said tool from said recess during a predetermined rotation on said shaft.

13. The invention in accordance with claim 12,

said jaws having said camming surfaces disposed in laterally apaced spaced 14. In a hopper discharge structure including a frame, a door hingedly connected to said frame for movement to open and closed position, mechanism for actuating said door whereby it moves by gravity to an open position including a shaft rotatably mounted on said frame, the improvement comprising:

said element including means rotatably connecting the same to said shaft and including a second pair of jaws defining a second recess,

said element having second camming surfaces disposed in cruciform relation but reversed in relation to said first camming surfaces,

said element being movable to a position whereby said second recess may be manually engaged by said rod and said element and shaft is rotatable only in a counterclockwise direction. 

1. In a hopper having a discharge opening for discharging material therefrom, a frame supported by said hopper, the improvement comprising: a door having a first hinged end and a second free end in opposition thereto, hinged connected means hingedly connecting said first end of said door to said frame for movement between open and closed positions relative to said discharge opening, other means on said frame supporting the second free end of said door in the closed position, means on said hinged connecting means providing generally limited horizontal movement of said door, and further means on the frame adjacent the second end of the door and pivotally connecting with the door intermediate it said ends for movingly carrying said door generally horizontally in a direction whereby said second end of said door is moved generally horizontally out of supported engagement with said other means supporting on said frame, whereby said door is pivoted at its first end by gravity to said open position.
 2. The invention in accordance with claim 1, said further means for moving said door including a roTatable member in said frame, an arm connected to said member for movement therewith, a link having one end pivotally connected to said door hinged end and another end pivotally connected to said arm, and said rotatable member during rotation moving said door to a closed position whereby said pivotal connection of said arm and link are moved to an overcenter position relative to the axis of said rotatable manner.
 3. The invention in accordance with claim 1, other said means supporting said second end of said door including a horizontally extending member on said frame including generally horizontal edge portions receiving the second end of said door in supporting engagement, and said second end being slidably out of said supporting during horizontal movement of said door.
 4. The invention in accordance with claim 1, said means on said hinged connecting means including a slot extending horizontally in the closed position of said door, and a slidable element on said first end of said door slidable disposed in said slot.
 5. In a hopper having a discharge opening for discharging material therefrom, a frame supported by said hopper, the improvement comprising: a door including means hingedly connecting one end of said door to said frame for movement between open and closed positions relative to said discharge opening, means on said frame supporting a second end of said door in the closed position, means on said hinged connecting means providing limited horizontal movement of said door, means for moving said door horizontally in a direction whereby said second end of said door is moved horizontally out of supported engagement with said supporting means on said frame, whereby said door is pivoted by gravity to said open position, said means supporting said second end of said door including a horizontally extending member on said frame including horizontal ledge portions receiving the second end of said door in supporting engagement, said second end being slidably out of said supporting engagement during horizontal movement of said door, said means on said hinged connecting means including a slot extending horizontally in the closed portion of said door, a slidable element of said one end of said door slidably disposed in said slot, said means on said hinged connecting means including a cylindrical hinge member supported on said frame, said hinge member having an opening, a second cylindrical hinge member rotatably positioned with said first hinge member containing said slot, said slot and said opening being in horizontal registry during the closed position of said door, and said slidable element being partially disposed in said slot and having said opening preventing rotation of said second cylindrical member.
 6. The invention in accordance with claim 5, said slidable element being movable horizontally with said door into said slot to one side of said opening whereby said means for moving includes a rotatable member which upon disengagement of said second end hingedly rotates with said door to said open position.
 7. In a hopper having a discharge opening for discharging material therefrom, a frame including horizontally spaced frame members disposed on sides of said opening, the improvement comprising: a horizontal support on said frame extending adjacent said opening between said frame members; a pair of doors, a hinge mechanism for connecting each of the first ends of each of said doors to each of said frame members for hinging movement between open and closed positions relative to said discharge opening, each said hinge mechanism including a hinge bracket connected to said respective frame member, a rotatable member rotatably supported on said hinge bracket, said rotatable member including a slot, a slidable element connected to said first end of each door engaging said slot in relative sliding relation, each said door including a second end supported on said horizontal support in the closed position of said doors, and means on said frame pivotally interconnecting with each of the doors intermediate their said ends for moving said doors horizontally whereby said second ends of said doors are disengaged from supported relation relative to said horizontal support and said doors are moved by gravity to an open position.
 8. The invention in accordance with claim 7, said means on said frame for moving said doors horizontally including a shaft rotatably supported on said horizontal support, a pair o arms projecting in opposite direction from said shaft and rotatable therewith, first and second links respectively connected to said doors, one link, in a closed position of said door, extending over said shaft and pivotally connected to one of said arms, said other link extending beneath said shaft and being pivotally connected to said other arm, and said pivotal connection of said links to said arms being disposed overcenter relative to the axis of said shaft.
 9. In a hopper having a discharge opening for discharging materials therefrom, a frame including horizontally spaced frame members disposed on sides of said opening, the improvement comprising: a horizontal support on said frame extending adjacent said opening said frame members, a pair of doors, a hinge mechanism connecting first ends of said doors to said frame members for hinging movement between open and closed positions relative to said discharge opening, each said hinge mechanism including a hinge bracket connected to said frame member, a rotatable member rotatably supported on said hinge bracket, said rotatable member including a slot, a slidable element connected to said first end of each door engaging said slot in relative sliding relation, each said door including a second end supported on said horizontal support in the closed position of said doors, means on said frame for moving said doors horizontally whereby said second ends of said doors are disengaged from supported relation relative to said horizontal support and said doors are moved by gravity to an open position, each said hinge bracket including a cylindrical member, said rotatable member including a second cylindrical member rotatably supported within said first cylindrical member, said slot being disposed in said second cylindrical member, said first cylindrical member having an opening in the closed position of said doors being in registry with said slot, said slidable element being disposed in said opening and slot in the closed position of said door whereby said second cylindrical member is fixed against rotation, and said slidable element being movable to one side of said opening into said slot during disengagement of said second end of each said door during movement to its open position.
 10. The invention in accordance with claim 9, said horizontal support including a plurality of horizontal ledges supporting the ends of said doors.
 11. The invention in accordance with claim 10, said supporting means having a rotating shaft supported thereon and means for moving said doors including linkages pivotally connected to said doors and said shaft.
 12. In a hopper discharge structure including a frame, a door hingedly connected to said frame for movement to open and closed positions, mechanism for actuating said door whereby it moves by gravity to an open position including a shaft rotatably mounted on said frame, the improvement comprising: an operating hear for rotating said shaft including arm means having an element carried thereby, said element having a pair of laterally spaced jaws defining therebetween an open end tool-receiving recess, each jaw having a camming surface, said jaws being disposed to rotate said shaft in one direction during the normal insertion of a tool withing saiD recess, and said camming surfaces being operative to disengage said tool from said recess during a predetermined rotation on said shaft.
 13. The invention in accordance with claim 12, said jaws having said camming surfaces disposed in laterally apaced spaced
 14. In a hopper discharge structure including a frame, a door hingedly connected to said frame for movement to open and closed position, mechanism for actuating said door whereby it moves by gravity to an open position including a shaft rotatably mounted on said frame, the improvement comprising: an operating head for rotating said shaft including an element having a pair of laterally spaced jaws defining therebetween an open end tool-receiving recess, each jaw having a camming surface, said jaws being disposed to rotate said shaft in only a clockwise direction during the normal insertion of a tool within said recess, said camming surfaces being operative to disengage said tool from said recess during a predetermined rotation of said shaft, said jaws having said camming surfaces disposed in laterally spaced cruciform relation, said element including means rotatably connecting the same to said shaft and including a second pair of jaws defining a second recess, said element having second camming surfaces disposed in cruciform relation but reversed in relation to said first camming surfaces, said element being movable to a position whereby said second recess may be manually engaged by said rod and said element and shaft is rotatable only in a counterclockwise direction. 